The present invention relates to the stabilization of aqueous dispersions. More particularly, it relates to surface active agents synthesized from maleic anhydride adducts of alpha-methylstyrene and alpha-methylstyrene dimer which are useful as stabilizers in rubber latex.
Various dimers of styrene and styrene derivatives are discussed in Griess, G. A., "Styrene Resins," in Styrene, its Polymers, Copolymers and Derivatives, Boundy, R. H. and Boyer, R. F., ed., Part II, pp. 812-814, Reinhold, N.Y., 1952 (hereinafter referred to as Griess).
The greater part of the work reported in the literature on reaction products of styrene and alpha-methylstyrene and maleic anhydride is on the subject of radical catalyzed polymerization. Relatively little effort has been devoted to investigating products other than copolymers.
Reactions between maleic anhydride and styrene and alpha-methylstyrene are the subject of several references. The addition of maleic anhydride to styrene is described in Patai, S. ed., The Chemistry of Alkenes, pp. 873-894, Interscience Pub., N.Y., 1964. An adduct of alpha-methylstyrene with maleic anhydride is mentioned in Onishchenko, A. S., Diene Synthesis, p. 494, Academy of Sciences of the USSR, Institute of Organic Chemistry, Daniel Davey Pub., N.Y., 1964. Other references to reactions between alpha-methylstyrene and maleic anhydride are: CA 37:5034 (1943); CA 45:9894 (1951); and U.S. Pat. No. 2,561,313.
An adduct between styrene and its homologs including alpha-methylstyrene dimer and fumarate esters is reported in U.S. Pat. No. 2,913,482.